SEATTLE -- After a frustrating stretch for lefty relief specialist Marc Rzepczynski, the Mariners designated the struggling veteran for assignment on Friday and recalled left-hander Roenis Elias from Triple-A Tacoma.
Elias, who was reacquired from the Red Sox on April 23, will be available in the bullpen for Friday night's series opener against the Rays at Safeco Field.
Rzepczynski is in the second year of a two-year contract that pays him $5.5 million this season. But the 32-year-old was 0-1 with a 9.39 ERA in 7 2/3 innings over 18 appearances this season, with 10 strikeouts and nine walks.
"It's been a struggle for him just getting the results that he or we were looking for," Mariners manager Scott Servais said. "This is a 'do good' league. You do good, you stay. It doesn't make it any easier with a guy who has that much service time and has been around. When you put the team together in the offseason, he certainly had a role. His thing is to get the left-handers out and he's been struggling to do that."
Rzepczynski is a 10-year Major League veteran who has pitched for the Blue Jays, Cardinals, Indians, Padres, A's, Nationals and Mariners, and he owns a career 3.92 ERA. His 501 MLB appearances are the fifth most among active left-handed relievers.

Seattle now has seven days to trade, release or outright Rzepczynski's contract to the Minor Leagues. His departure opens a spot on the 40-man roster, which now is at 39.
"I still think he's healthy and has plenty of arm left," Servais said. "I think Zep will get back in the league and if he doesn't get claimed by another club, we certainly left the door open for him to go to Tacoma and pitch for us there. I'd love for him to do that, get it going in the right direction and get him back here, but that decision will be up to him."
James Pazos had replaced Rzepczynski as the club's late-inning left-handed setup man in recent weeks, and Elias now will fill the second lefty spot in the bullpen, with the ability to pitch longer outings as a converted starter.
"He's not just a left-on-left guy at all because he can get out righties as well," Servais said. "It gives our bullpen a little more flexibility with another guy that can do more than just face a left-hander here or there."
Elias, 29, went 2-4 with a 4.94 ERA with 27 strikeouts and 12 walks in 31 innings over seven games, including six starts, for Tacoma. In his last outing on Wednesday at Las Vegas, he tossed 6 2/3 scoreless innings, allowing one hit and three walks while striking out three.
Prior to being acquired by the Mariners, Elias was 1-0 with one save and a 1.23 ERA with nine strikeouts and two walks in 7 1/3 innings in four games as a reliever for Triple-A Pawtucket.
Elias was a starter in Seattle in 2014-15 before being traded to Boston. But he spent most of 2017 on the disabled list while dealing with a strained oblique, and the Red Sox traded him back to the Mariners this year for cash or a player to be named.

"I feel very fortunate because sometimes you stop and think you might not get another opportunity to get back here," Elias said through interpreter Manny Acta. "I worked very hard over there, but the door didn't open for me. I feel very good to get another chance here, because I've always liked it here. The call yesterday made me very happy and caught me by surprise because I didn't think the opportunity was going to be this fast."
Worth noting
• Catcher Mike Zunino was out of the lineup Friday after feeling some tightness in his right quadricep muscle during Thursday's game, but Servais said it was strictly precautionary and expects Zunino will be fine to catch both Saturday and Sunday before Monday's off day.
• Mariners shortstop Jean Segura ended May with the highest batting average in the AL for the month at .382, while Ben Gamel was ninth at .343.
• Seattle had three of the top nine ERAs among starting pitchers for the month, with James Paxton third at 1.67, Wade LeBlanc fourth at 1.72 and Marco Gonzales ninth at 2.30. Houston's Justin Verlander topped the list at 0.86. Paxton and LeBlanc finished with the fifth and sixth best ERAs for May in Mariners history. Erik Bedard holds the top spot at 1.39 in 2011.